Clair Bros Amp

[WOPL Sniffer]

This should be fun. Any good info on Clair Bros amps? I got a couple coming. It's got a few war wounds from Black Sabbath and others but hey.....

 

[laatsch55]

They had a few tweaks to the driver board, and a much more robust Zoebel network.

 

[laatsch55]

They were usually balls to the walls at 4 ohms and the stock Zoebels couldn't handle the high freqs at that power. So they put a 20 watt steel case resistor for the Zoebels resistor. You should notice some different components on the boa r d and possibly some R/C pairs on the foil side.

 

[laatsch55]

Post some pics when you open it up...

 

[Northwinds]

Very cool Perry!

 

[WOPL Sniffer]

The others in the stacks seem to be in better shape. They are being packed for shipment right now. Got some hulks for parts coming too.

 

[laatsch55]

PL36 driver boards?

 

[WOPL Sniffer]

Not sure yet. 14_20's if I have my way. What year did they switch?

 

[laatsch55]

Not sure. Are they fully comp??

 

[WOPL Sniffer]

Don't know..... For what I have planned, I wasn't worried about that. I'm getting the band back together man.... Gonna be the loudest kazoo band in history..... That and I play lead comb w/wax paper.

Seriously, I don't know Lee. I would assume with them being spec'd by Clair that they would be but not sure. You know more about these things than I do. All I know is I'm gonna have a stack of them and don't know what is in store for them. I know that I will be building 4 "Perry's Special Edition" amps for me. I just ordered some goodies.

 

[laatsch55]

I hear ya bud..

 

[WOPL Sniffer]

plus I'll have something to barter with for hard to find items.

 

[WOPL Sniffer]

PL36 driver boards?

Lee, after scrutiny, the boards do indeed appear to be PL36 control boards. Is that significant?

 

[Gepetto]

Lee, after scrutiny, the boards do indeed appear to be PL36 control boards. Is that significant?

That is the board that was in all Series 2 amps Perry.

 

[oldphaser]

Clair Brothers / Phase Linear 700 Series Two Amplifiers

All Phase Linear 700 series II amplifiers had PL-36 p.c. boards in them. If my memory serves me correct the Clair Brothers amps were all fully comp amps. Typically using NEC 2SD555's with 2SB600 output transistors. Later 700 series II's like the PRO 700's had the pro version PL-36 pc board with wider traces and the ceramic disc (slow down) capacitors already installed.

The amplifiers in the photos appear to be the transition into the PRO700's. The amp more than likely has press nuts with machine screws instead of sheet metal screws. The chassis may even be a steel chassis and not aluminum. I also see the larger 50 watt Dale resistors in the RC (Zoebel) network. This is because Clair Brothers drove the amp into clipping at 20KHz at 4 ohms. By the way, I have a spare supply of these Dale resistors available.

The Clair Brothers amps were spec'd to do 700 watts (single channel driven) into a 4 ohm load. Dean has a Clair Brother spec sheet that all the amps had to meet before they were shipped out. I will see if I can obtain a copy. NOTE: Clair Brothers later used the Dual 500's on the Pink Floyd "The Wall" tour.

Since these amps are coming from Hawaii, I would expect that they have a fair amount of rust due to their proximity to salt water.

Ed

 

[laatsch55]

Thanks for clearing that up Ed!! 700 with only one channel driven?? What was the rationale for that?

 

[WOPL Sniffer]

Thanks Ed, I also found out, I get 2 500's one is complete working, and 14 more Series 2's regular ( not Clair) in various states of repair, along with the 16 Clair's. I think a few of them I'll put on the bay "as is" for collectors if there is any interest. Most of them if not all, work but have been sitting so beware when bringing them up. I'm gonna need a trailer when they get to the freight yard in about 2 weeks.

 

[Gepetto]

Thanks Ed, I also found out, I get 2 500's one is complete working, and 14 more Series 2's regular ( not Clair) in various states of repair, along with the 16 Clair's. I think a few of them I'll put on the bay "as is" for collectors if there is any interest. Most of them if not all, work but have been sitting so beware when bringing them up. I'm gonna need a trailer when they get to the freight yard in about 2 weeks.

Quite a haul Perry...

 

[laatsch55]

Indeed!!

 

[grapplesaw]

The units look very clean. Ed is right about Hawian air being salty and wet but those look like they have been well looked after. PM me please what you may want to sell. My 500D is looking for a mate